o2pp 1.4ata+?

[Wijbrandus]

@Cameron

So you think "mindless rule following" is a bad thing?

Seems to me if you don't know everything about the subject, following the established guidelines is the wise way to go.

I for one doubt I'll ever know enough about this to really push the limits. I just don't see a need. There's too many ways of keeping your ppO2 under 1.4 to bother.

 

[Uncle Pug]

Eliminate all chance and stay in bed.

But then I've done CPR on more folks who had the big one in bed than I have on folks who were diving.

 

[jakubson]

Maybe this depends where you do the liveaboard? In Thailand I could have any mix I wanted - although I agree 32% was probably the norm. However we were doing quite a number of deep dives and I had my computer up to 70% on two of the 6 days. Sure I was spending a lot of time deep (photographing Leopard sharks), but I had a large 15ltr tank so it would have been easily possible to push it too far.

I looked over my logs from the last two liveaboards, where I know I reached 60% to 70% on the 24 hour clock. I was doing 5 dives per day. My AVERAGE depth (according to the computer) on the multilevel profile was 41 feet (typical max depth was 75 feet), with average bottom time of 58 minutes. We were diving 32%. So my Average PO2 was 0.72, which allows a 24 hour clock of about 500 minutes. Since my average 24 hour bottom time was 290 minutes, I reached about 60% on my clock. Note that once this is reached, it tends to stay there, since each "new" dive replaces an "old" dive on the clock. So my clock would vary up to 70% (if the "new" dive was deeper than the "old" dive) but no further. On the nitrogen side, I was never "out of the green" on the bar graph.

 

[ShakaZulu]

I don't know enough about the subject to play on that field, thus I stick to what I was taught.

 

[Charlie99]

How many incidents of Ox Tox have occured at a PO2 of 1.6?

I do recall an incident a few years ago where a guy doing the Andrea Doria toxed during a 20' O2 stop.

Far more common are incidents where someone is breathing something other than what they thought --- either because of misanalysis, NO analysis, or accidently breathing a deco bottle while deep.

 

[StSomewhere]

I do recall an incident a few years ago where a guy doing the Andrea Doria toxed during a 20' O2 stop.

IIRC, I thought he was actually diving a 2.0 ATA bottom mix, not at 20' on O2. :06:

 

[Charlie99]

IIRC, I thought he was actually diving a 2.0 ATA bottom mix, not at 20' on O2. :06:

Probably different incidents. The one I recall was reported on rec.scuba, and was non-fatal IIRC.

More typical, though, seem to be cases like the GUE rec triox / tech 1 course incident in Europe, where the mix he was breathing was 50% O2 rather than the 30/30 he thought it was.

 

[SeanQ]

Eliminate all chance and stay in bed.

But then I've done CPR on more folks who had the big one in bed than I have on folks who were diving.

What pp02 were they at? Were they in the working portion of the dive or resting during deco?

 

[Land Locked]

What pp02 were they at? Were they in the working portion of the dive or resting during deco?

Sometimes I think Pug is just trolling!

 

[Uncle Pug]

I actually had one of those. Very sad. He didn't make it.